DE1435611A1 - Synthetic fiber and manufacture of the same - Google Patents

Description

P 14 35 611. 7
New documents

EI DU PONT DE NEMOURS AND CQMFkWi lOfch and Market Streeto, Wilmington, Delaware 19898, V.St.A.

Synthetic fiber and manufacture of the same

The invention relates to new and valuable fibers or threads of polymers and copolymers of acrylonitrile, in particular Fibers or threads of these fibers with a hollow void free from height Type and production of the same "

Shrinkable fibers made from polymers of Acrylnltrile have been known for some time * high-ear inoculation fibers «d. H. Fibers with a visual pumping ability in the order of about 35 and higher »dyke them. desirable properties more conventional Having polytetrafluoroethylene fibers have not yet become known. Try «to produce such fibers that a soft Or! ff ^ a high weather resistance ;, a high resistance and freedom from interior spaces

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have solidified structure have so far not been successful guided. Maintaining the solidified structure has proven to be one of the most difficult problems

The void-containing fibers produced so far have not worked proved completely satisfactory. Due to their porous structure, they tend to adsorb finishing oils and other treatment agents. If these agents remain on the fiber surfaces * they are no longer available to give the fibers the desired properties, e.g. B. antistatic properties and the like to give. Step into the bottom line problems in fiber processing. In addition, with some types of fabric it is important that the fiber not structure is porous. The porosity of a porous fiber and thus its opacity can be altered by subsequent treatments * - ie washing and Ironing, be influenced. As a result, fabrics made from such fibers show undesirable color and dyeing properties in use Changes in oil.

The present invention provides fibers made from polymers of acrylonitrile which are characterized by a negative birefringence and a shrinkability of at least 35 % . Such fibers have a consolidated or void-free structure and show a special fourth in the production of pol, and pile fabrics, particularly those. in type of artificial furs Preferably, the polymer of acrylonitrile, a mixed polymer containing at least about 70% of acrylonitrile and up to about] 50 £ of a Stfaylenartig unsaturated mlsehpolymerlsierharen with acrylonitrile monomers contains.

The production of these high-necked, void-free fibers or threads can be carried out in a further embodiment of the invention by drying the solvent-free, unsuitable

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stretched acrylonitrile threads at a temperature of about 100 to 130 ⁰ C reduced the moisture content below 10 % "the treated out at least 15 seconds at a temperature" door between about 96 and 110 ⁰ C treated with an aqueous medium and then the threads on the about 1 , 5 »to 2.5 times its original length reokt.

Solvent-free is understood to mean threads from which the detergent has been removed to such an extent that the remaining amount does not interfere with normal use of the fiber, ie threads whose content of the original solvent is about 5 % or less. Undrawn threads are to be understood as meaning those which have not been subjected to any significant permanent stray bog. When the original thread material obtained from the spinning machine is extracted in the form of the spun pack in order to remove spinning solution, it shows no stretch at all. On the other hand, if the originally spun for solvent removal is unwound from the package obtained during spinning and continuously passed through an extraction bath or if it is passed through an extraction bath immediately after leaving the spinning device in order to remove the solvent, a slight stretching can occur. This is because the fiber must be kept under sufficient tension for proper winding. Threads made in this way fall under the definition of undrawn threads.

Various methods are available for determining whether a fiber has a consolidated or void-free structure. Kan can, for example, be the area ratio or the Use the ratio of the measured fiber area to the calculated fiber area to show the type of structure. A low area ratio shows a solidified structure

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an * The color density is also a good indicator for the degree of consolidation of the structure when fibers of the same chemical structure can be compared «For a given type of polymer, the higher the density, the less hollow Structure. A fiber made from a mixed polymer of acrylonitrile Made with a comonomer like vinylidene chloride *, however, has a higher density than a fiber made from a copolymer of acrylonitrile ^ with a corresponding amount of methyl acrylate. This requires an extraordinary one Exercise care in using dens.

It has been shown that the slg @ nsehaf for the birefringence of the thread material can conveniently be used for a precise definition of the solidified structure of the products of the invention. This property has proven to be essentially independent of the composition of the polymers and copolymers in the context of the invention. Unlike most fiber-like materials, solidified fibers made of polymers of acrylonitrile, which have been subjected to even a slight stretching in the longitudinal direction of the thread, have a negative birefringence. The negative birefringence is apparently based on the strong polarizability of the nitrile groups, which are oriented in a direction perpendicular to the fiber axis due to the orientation of the polymer core molecules in the direction of the thread axis. Any degree of negative birefringence results in a usable solidified structure . In contrast, the oriented porous or void-containing fibers or filaments from the formation of the acrylonitrile show a positive birefringence. Methods for determining the birefringence are known! Descriptions of suitable processes can be found in _Preston's "Modern Textile Mieroseogy ⁸ ',, Emmott & Company, Ltd., London 1953, and in Heyn," Tesöil ©! © Journal * ^1, 22, 5 * 3 (1952).

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When practicing the method according to the invention, the threads can be produced using the wet or dry spinning technique. To remove the solvent, the spun material is passed through an aqueous bath preferably being maintained at a temperature between room temperature and about 100 ⁰ C. After reducing the solvent content to about 3 0EW »£ or less of the water content of the filaments by Trooknung at temperatures between about 100 and 150 ⁰ C to less than about 10 wt. # Is decreased. The extraction of the solvent can take place at relatively very low temperatures, but it is important that the fibers remain essentially non-stereo during such a treatment and that the drying takes place within the above-mentioned temperature range.

The dried threads are then treated in a hot aqueous medium. As shown in more detail later, the dried threads must be exposed to the hot aqueous medium for at least about 15 seconds. Aueserdem of the treatment medium the temperature must be about 96 to 110 ⁰ C. After this treatment in a hot aqueous medium, the fibers must be stretched to around 1.5 to 2.5 times their original length. The threads obtained in this way have a solidified or void-free structure and a shrinkability of at least about 25 %. The shrinkage of the fibers can - as described in more detail below - be brought about by allowing a heated atmosphere to act on a substance containing them.

The following examples serve to further explain the Invention without, however, exhaustively characterizing the same. Unless otherwise stated, part and prosent information are based on weight.

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example

By dry spinning a solution © is @ s terpolymers from 94.0 j acrylonitrile, 5 * 7 $ AcrylsSureinethylestei? and © _e 3 % Natriurastyrene sulfosaafe, © in various faei @ nkab © l of 44 400 tex i @ a) b @ i of a läasolfadentiter voia 0.44 tex (4 den),

äiweh masses as! isungsnl% fe§liVai @ n samples, produced ο Bas Ksfe © a -aiFä i & as ⁸ extraction! d @ s LSsimgsmittela dureh © in® H @ lte ψ & ε miiMk ^ cwnm g © fün »t ₅ iie wfess'iga Diajefehylfona-

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14J ⁰ C your density is 1.183 g / cm ^. After shrinkage in boiling water, the single threads have a titer of 0.3 tex (2.7 denier).

The main part of the cable is at 60 ⁰ C a crimping machine and then to 3 »2-cm staple cut" This stacked with different amounts of Polyaorylnitril staple fibers from 1.5 to 2.2 tex (14 bla 20 den) and a shrinkage mixed in boiling water of less than 3 %. Pile knitted fabrics are produced from the mixtures and these are then heat-treated in order to shrink the high-waisted fibers.

The fabrics obtained are fur-like and have the effects of soother hair.

Example 2

A dry, solvent-free, essentially uncovered tow of polyacrylic filament is prepared as in Example I. Dan Xabel is. Boiled for 5 minutes in water and then stretched in water at 75 · ⁰ C to 2.12 times its original length. The product gives $ 40 shrinkage in boiling water. All tested threads show the negative birefringence. The density of the threads is 1.172 g / cm **.

AIa Kontrollverauoh, the importance of the above The following experiment shows the sequence of work stages for obtaining a product with the desired properties carried out:

Daa getnäas Example 1 spun, still containing solvent-containing cable is stretched to 2.1 times its original length by passing it through a series of nine tanks, the

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aqueous Dlmethylformamidlosungen of 70 ⁰ C and which contain Dimethylformamidkonzentration is lower in successive tanks and is in the last tank is substantially zero. The warm, wet tow is fed directly to a stuffer box crimper and, after crimping, is cut into 3.2-em stacks. The cut stacked goods are dried ^{at 30 ° C. in an oven.}

The product containing less than 3 £ dimethylformamide, has a linear density of 0.21 tex (1.9 denier) results in a shrinkage in boiling water of 38% and at Trookenbedingungen at 143 ⁰ C such of 34.5%. In spite of the fact that the product has the same chemical composition as in the preceding examples, its weight is only 1.138 g / cm and its birefringence is positive and equal to +31 millimicrons.

Example 3

There is produced a dry, solvent-free, ungereoktes substantially cable by extracting a spun from the polymers of Examples 1 cable continuously at 90 ⁰ C, where the cable leaves the treatment with 114.3 m / min * and a 34 £ strength Stretching is done to maintain proper tension on the cable for ease of use. After extraction, the tow has a denier of 58,000 tex (520 denier); the titer of its individual threads is 0.33 tex (2.9 denier). The extracted cable is ^{dried at 127 °} C. for 4 minutes; it then contains less than 1 % moisture and 1.4 % dimethylformamide.

The dried tow is then passed through a maintained at 96 ⁰ C aqueous dyeing liquor containing per liter of 50 g Xthylenoarbonat, 40 g of the dye "Brilliant Oreen Crystals ¹ * (Color Index 662)

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and contains enough kiaeasig to give a pH of 5. Immediately upon leaving the liquor, the cable is passed through a pipe containing atmospheric steam of such a length that the steam acts on the cable for 3 minutes. The cable is then "wipe to 116 ⁰ C heated metal plates to 1.9 times its stretched length ursprUngliohen. The dark green product has 38.8 % shrinkage in boiling water and negative birefringence. After crimping and simmering, the green-colored staple material is mixed with low-crinkling staple fibers; The fiber material is processed into pile goods, which after boiling treatment are unusual surface effects due to the different shrinkage of the two fiber components.

If the extracted dry tow is stretched between heated plates without prior passage through the dye liquor and steam treatment tube, the stretching treatment is difficult to carry out due to thread breaks and the product shows a shrinkage below 34%.

Zn a number of other experiments, it is determined that the minimum contact time with hot aqueous f11essfähigem medium like that is required to obtain a product having a shrinkage (NaOH stretching) of more than 35%, 15 seconds, and that the minimum temperature of this aqueous flowable medium 96 ⁰ C. Such high temperatures such as 110 ⁰ C affect nioht harmful, and so long as Einwlrkungszeltea 3 Standen prove to be satisfactory. Both hot water and hot aqueous solutions are common! » Textile treatment agents as well as steam prove to be more satisfactory media for the treatment of the unpaired outer surface before the routes.

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A -425 Example 4

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A jJO-filament polyacrylonitrile fadan material (30 tex equal to 270 denier) is collected on a perforated spinning bobbin and ^{extracted on the bobbin with water at 95 °} C. until its solvent content is below 2 % . The unstretched product is threaded disgusted into strands, which are dried for 1 hour at 100 ⁰ C in an oven. The tresses are then boiled for 50 minutes each in an aqueous solution containing an excess of the blue disperse dye "Prototype 62". The threads of the various strands are allowed to dry at room temperature and are then stretched between heated plates at various drawing ratios and at various drawing temperatures. Plate temperatures between approximately 118 and 138 ^° C. have proven to be satisfactory. The stretching treatment is not satisfactory outside of these limits due to excessive fractures. Samples stretched to 150 or 250 of their original length show shrinkage values in boiling water between 35 and 36 % * Stretched to less than 150 % or more than 250 % of the original length · Samples show shrinkage values below 35 % · Samples stretched to more than 150 % show increased shrinkage of up to 42 % for a sample that was »stretched to 190% of its original length. The shrinkage then decreases with increasing stretching.

All of these samples have negative birefringence and a density greater than 1.8o g / cm *.

The practical implementation of the invention is above on the basis of dry-spun threads made of polymers of acrylonitrile explained, but the invention wet spun threads are accessible in the same catfish. Same as the dry-pinned property The wet-spun threads must be solvent-free, dry and

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be essentially non-stereo before it is subjected to treatment in deaf's "hairy medium", which in turn is followed by a slight spread. It is possible to work with polyacrylonitrile as well as with copolymers which contain at least about 70 % acrylonitrile and up to about 30 % of any old acrylonitrile misohpolymerizable, neutral, monounsaturated monomers such as ethylene-like, such as vinyl acetate, methyl vinyl ketone, arylic acid methyl ester, methyl methacrylate, vinyl chloride such as vinylidene chloride also other monomers of the type described in the USA patent No. 2,436,926. It is also possible to work with small amounts, ie up to about 10 pounds, of cationic and anionic monomers, such as sodium styrene sulfonate or 2-vinylpyrldine, in order to improve the color acceptance to enhance. Folyaere 85% or more acrylonitrile is commonly used for best strength, insolubility and resistance to sunlight.

The dough process is krltiaofa for the extracted non-stereoscopic thread material. Temperatures above l> 0 ⁰ C should be avoided, you aie leioht discoloration dea Paser- or thread Good veruraaeben. Blue price exposure to temperatures in the WBm dleaea value 1st. however not undesirable. Longer drying can also be carried out at temperatures as low as 100 ° C.

Sa iat critical, the concentrated, solvent-free dry Filament represents the strengthening of an aqueous, flowing medium suspend at Twpeiatuien near the boiling point before the Ftden fjasjirault «earth. The treatment medium can be water, DaMDf or wSesrlge readings of typical textile treatment agents, «Ie Parbatoffe, Wasohalttel, WelohoAchungsmlttel etc., use

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the. The treatment medium must have a temperature between approximately 96 and 110 ^° C .; Temperatures between approximately 96 and 102 ^° C. are preferred. The treatment time can be approximately 15 seconds to approximately 2 hours or more.

After the treatment with the hot aqueous Behändlungsmit = tel to the threads 1 have about 50 stretched to 150%, ie, they are intended to about 1 "5 ° to 2. 5 ~ _e times its original length to be stretched. If desired, "the threads can be dried between the cook" and the stretching treatment, which is generally preferable for ease of use when the stretching is carried out in a non-aqueous medium.

The stretch given to the thread should be between about 50 and 150 % . During the stretching, the thread material should be heated to the minimum temperature that allows satisfactory work. If the stretching is carried out in an aqueous medium, a temperature of about 70 to 80 ^° C. is sufficient; this temperature range is preferred, although a work in the wider portion VCN 60 to 90 ⁰ C in general is satisfactory .. Vfenn the stretching in Keisaluft., such as between heated Piatfter ·., takes place, has the Luffc a higher temperature than the Nassreeken «Plate temperatures of about .13.8 to 138 ⁰ C have proven to be satisfactory. The temperature used depends on the length of the heating zone and the speed "fa" with which the material to be treated moves through this zone. It is preferable to operate at the minimum temperature which allows the stretching treatment to be carried out satisfactorily.

If the high-shrinkage thread material is to be used in Fedenform, it can be stretched to a pack on = wrap. In general, it is orwünsoht-, a textile finish.

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feed »before winding the thread onto the package. If the high-necked thread material is desired in staple fiber form there is generally a ripple and then sons on Pile necessary. Because of the inherent shrinkage of the thread material, the crimping should be carried out at the lowest temperatures that allow comfortable working «

The fibers or threads according to the invention have a high Value in the form of knitted, woven and pile goods · In all cases they can be used to achieve desired effects achieve that cannot be achieved in any other way If mixed and produces yarns from the mixtures, the yarns can be used for loosely constructed knitted fabrics and fluffy fabrics which shrink under the influence of boiling water or dry heat to form goods which, due to the soles and loops formed by the low-shrink fibers when the high-shrink fibers shrink, have an unusual bulk and opacity to have.

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Claims (10)

H35611 P 14 55 611. 7 April 21, 1969 E. I. du Pont de Neciours and Company. A-425 (P 24 411) claims 1. Fiber or thread made of inem polymers of acrylonitrile, characterized by eisae negative birefringence and a Shrinkability of at least 33 ^ * 2 »fiber tosw» thread according to claim 1 * characterized in that the polymer d®s aerylnitrile is a mixed polymer »which contains at least 70 % acrylonitrile and up to 50% ethylenically unsaturated monomers which can be polymerized with aoryl nitrile. 5 · fiber or thread according to claim 2 _S characterized in that the mixed polymer contains at least 85 % acrylonitrile. 4. fiber or thread according to claim 2 upper 3 »thereby gek ermisst ehnet * that one of the ethylene-like unsaturated monsters of the Acrylic Muremethylestei- * is. 5. fiber bsw. Thread according to claim 2 or 3 » characterized in that one of the monomers is a salt of styrene sulfonic acid *, in particular in an amount of about 0.1 to 5 % . 6. A process for the production of fibers or PSden according to claim 1 to 3t characterized in that the moisture content of erspormenen in a verifiable manner known per se 009 811/1075 "1 it" ^. 8AD H35611 non-stereo, solvent-free goods reduced by drying at a temperature of about 100 to 130 ° C to below 10 £, the dried goods then ^{treated for at least 15 seconds in an aqueous medium at a temperature of about 96 to 110 0} C and then to the about 1 Stretches, 5- to 2.5-fold of its original length. 7. The method according to claim 6, characterized in that the aqueous medium is applied at a temperature of 96 to 110 ⁰ C, 8. The method according to claim 6 or 7, characterized in that the dried out is treated in boiling water for 15 seconds to 2 hours. 9 · A method according to any of claims 6 to 8, characterized labeled in »characterized in that the stretching is carried out in an aqueous Mediufs at a temperature between 60 to 90 ⁰ C. 10. The method characterized naxAi one of claims 6 to 8, characterized marked in 'that the stretching takes place between a -Temperature of about 118 to I38 ⁰ C heated plates. 0098.1 ^ 1075